How to create a List of size N in Java

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How to create a List of size N in Java ?

Answer

To create a list of size N in Java, you can use the Arrays.asList method or the Collections.nCopies method.

✐ Examples

1 Create a List of Size N with Default Values Using Arrays.asList

In this example,

We use the Arrays.asList method with an array of default values to create a list of size N.
The Arrays.asList method returns a fixed-size list backed by the specified array.
Finally, we print the created list to standard output.

Java Program

import java.util.Arrays;

public class Main {
    public static void main(String[] args) {
        int size = 5;
        Integer[] array = new Integer[size];
        Arrays.fill(array, 0);
        java.util.List<Integer> list = Arrays.asList(array);
        System.out.println("List of size " + size + " with default values: " + list);
    }
}

Output

List of size 5 with default values: [0, 0, 0, 0, 0]

2 Create a List of Size N with Default Values Using Collections.nCopies

In this example,

We use the Collections.nCopies method to create an immutable list containing N copies of the specified object.
The Collections.nCopies method returns a fixed-size list that contains N copies of the specified object.
Finally, we print the created list to standard output.

Java Program

import java.util.Collections;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        int size = 5;
        List<String> list = Collections.nCopies(size, "");
        System.out.println("List of size " + size + " with default values: " + list);
    }
}

Output

List of size 5 with default values: [, , , , ]

Summary

In this tutorial, we learned How to create a List of size N in Java language with well detailed examples.

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How to create a List of size N in Java

How to create a List of size N in Java ?

Answer

✐ Examples

1 Create a List of Size N with Default Values Using Arrays.asList

Java Program

Output

2 Create a List of Size N with Default Values Using Collections.nCopies

Java Program

Output

Summary

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